Improvement in braces for bits



SLQRUNDLETT. BEACH FOR BITS.

m 77,219. Patented Apr. 28,' 1868.

,, Mtg

SAMUEL o. RUNDLETT, OF PORTLAND, MAINE.

* Letters Patent No. 17,219, dated April 28,1868.

IMPROVEMENT IN BRAGES FOR BITS.

ililn grinds-taunt is hi tips: with; than nut uniting put at ti e sameTO'ALL WHOM'IT MAY CONCERN:

Be it known that I, SAMUEL C. Runnnnrr, of Portland, in the county ofCumberland, and State of Maine have invented a new and useful ImprovedBit-Stock; andI hereby declare the following to be a full, clear, andexact description thereof,.which will enable others to make and use myinuentiom-reierenec being bad to the accompanying drawings, forming partof this specification, in whieh-- Figure 1 is 'a side sectionalelevation. I

Figure 2, a plan of the slide or holder.

The operation of my invention is as follows: Through the head of thebit-stock, seen at a, fig. 1, into which the end, f, of the bit fits, Imake aslot, b, somewhat wider than the cavity 'm, containing the head fof the borer. In this cavity is fitted a slide, a, which is shown inplan in fig. 2, in which there is a slot, d, 02' a proper size to admitthe head of the bit. On the lower side of the slot, this slide'ischami'ered, as shown at a and a corresponding out made in the bit. Atone extremity of the slide is a shoulder, 7:, to prevent it fromslipping to i'itt into the stock, and at the other is a rod, 2',provided with a screw thread, and a thumb-screw, j. Around this red isarranged a spiral spring, k, which tends to keep the slide 0 in thestock, whether the bit or borer is in place or not.

When a tool is to be put into the bit-stock,- it is only necessary toslip it into the cavity m, when the end of the bit, coming against thechami'ered edge of the slide, will force it back till it strikes the outmade in the hit-head, when, acted upon by the spiral spring k, it willbe drawn forward and caught therein, securing the hour firmly in itsplace. When is is desired to change the instrument, by pressing thethumb on the thumbscrew j, it will be forced into the position shown bythe dotted lines, fig. 1, when the tool may be readily drawn out, andthe slide will resume its former place. The object of providing theendoi the rod 1' with the thumbscrew j is that the spring'may be readilytightened, it it should work loose, by a turn of the screw j. This willbe found a great advantage; j

The peculiar points of my invention are its simplicity, rendering itless liable to get out of order, or wear out the arrangement of itsparts allowing it to be readily got at, and-the accuracy with which thecut or shoulder may be made-in the bit or borer.

To fit a bit to this stock, the slide c is to be removed by taking oiithe thumb-screw j and slipping back the slide, and the bit-he'ad is putin its place in the cavity m. Then a knife, or other marking-instrument,may be passed through they slot b, in which the slide c moves when inplace, and the exact place upon which the chamfered edge e will strikewhen it is in the slot can be readily and accurately marked. This is ofgreat practical value. g I

It will be seen that the slide 0 has no tendency to get loose, pressing,as it does, allthe time upon the borer, except when ptished outwardly bythe hand on the thumb-plate. I

I do not claim securing the borer in' its place by a slotted slide,neither do I claim an automatic bit-brace; I do not claim theimprovement of Horace Lettington, May 13, 1856, No. 14,876, where thebit is held by a rod or arbor, passing through the stock or hit andsportion of the socket, the arbor having a notch, as well as the shankofthe bit, with a bolt pressing against the same.

I also disclaim the patent of L. L. Pollard, No. 32,890, July 23, 1861,where an anger is held in a. handle by a swinging pawl,-having aprojection fitting into a notch on the auger-shank, which pawl is keptpressed against the shank by a thumb-piece, which is operated by avertical spiral spring. This is diiierent from mine in that, in mine,the spiral operates directly upon a horizontal slotted slide, whichencompasses the shank of the bit; but

What I do claim, and desire to secure by Letters Patent, is- Thearrangement, in the horizontal slot'b, of the slide c, having'theshoulder h, slot d, edge a. rod 2, spiral is, and adjusting thumb-piecej, as and for the purposes set forth.

SAMUEL G. RUNDLETT.

Witnesses:

WM. H. Cmrroso, WM. FRANK Sssvsr.

